Recently, as display technology has evolved from full-high definition (HD) to ultra HD (UHD), etc., a UHD television (TV), a UHD monitor, etc. have been developed. UHD is a display technology implemented using a number of pixels which is four times the number of pixels of Full-HD. Display devices with a large number of pixels, e.g., Full-HD display devices or UHD display devices, are capable of minutely displaying even a fine part of an image. Thus, details or sharpness of an image is one of the important issues for realistically displaying images. In particular, the details or sharpness of the image is closely related to edges included in a scene of the image. When a scene of an image includes many edges, display devices use many hardware resources to process the image. Information regarding the edges included in the scene of the image, i.e., whether the scene has high-frequency characteristics or low-frequency characteristics, is important for display devices to more efficiently use hardware resources and more realistically display the image. Accordingly, various researches have been conducted to accurately and efficiently analyze the frequency characteristics of scenes of an image.